To increase the filling rate of fibers for the purpose of enhancing the adsorption performance of the purification column, the adjacent fibers tightly adhere to each other as compared with the circular yarn in the case of the modified cross section yarn, whereby the surface area is easily lost. The present invention provides a purification column containing a porous fiber and a fiber bundle and a fiber bundle in which adhesion between adjacent porous fibers is suppressed and which has excellent removal performance of adsorbed substances.SOLUTION: The porous fiber has a solid shape and satisfies the following (a) to (c). (B) When the cross-sectional area of the cross section is Sf and the area surrounded by the circumscribed circle of the cross section is So, the circumscribed circle occupancy Sfo expressed by the following equation becomes 0.70 or less, circumscribed circle occupancy Sfo = Sf / So (c) Specific surface area is 5 m2/ G or moreBACKGROUND OF THE INVENTION【課題】浄化カラムの吸着性能を高める等の目的で繊維の充填率を高めると、異形断面糸では円形糸に比べて隣接する繊維同士が密着することで、表面積をロスし易いことである。本発明は、隣接する多孔質繊維同士の密着が抑制され、被吸着物質の除去性能に優れた、多孔質繊維および繊維束、ならびに繊維束を内蔵した浄化カラムを提供する。【解決手段】中実形状であって以下(a)~(c)を満たす多孔質繊維。(a)横断面の形状が、回転非対称形(b)横断面の断面積をSf、横断面の外接円で囲まれる面積をSoとすると、以下の式で表される外接円占有度Sfoが0.70以下、外接円占有度Sfo=Sf/So(c)比表面積が5m2/g以上【選択図】図1
